Banksy's month-long 'residency' on the streets of New York City continues to produce marvellous and witty artworks, with the latest additions including a patched-up, balloon-shaped heart and a mobile truck delivering "calm" across the Big Apple.

According to the artist's website, his delivery truck appeared this weekend and will tour New York City. The vehicle has been turned into a garden oasis of sorts, and is inspired by John Steinbeck's classic American novel The Grapes of Wrath.

A self-deprecating audio guide on the website introduces the work as follows: "The artist claims to have been inspired to create this piece after listening to a poem by Keats. Sorry, I misread that… The artist was p***** when he made this and it's incomplete."

The graffiti-covered truck boasts, "…a digitally remastered sunset that never sets, a waterfall pumping over 22 gallons of water per minute and a couple of plastic butterflies duct-taped over a fan that move around a bit."

The voice-over draws an "interesting, if not altogether successful" comparison between Banksy's illegal use of abandoned city space to create artworks and "the acts of farmers of the Great Depression who, being kicked off their land by large corporations, took to sowing seeds illicitly."

The Steinbeck novel follows a poor farming family in Oklahoma, where dustbowl conditions and the increasing prevalence of large machinery conspired to force farmers off the land.

In the book, swathes of food are left to rot, and vast tracts of land go unused since no profit can be drawn from them.

As the exiled farmers longed to illegally till the wasted fields, so Banksy reclaims unloved walls and buildings.

Today, another, seemingly simpler work appeared in Brooklyn. It shows a heart-shaped helium balloon covered in plasters.

According to the voiceover on the artist's website, it depicts the "battle to survive a broken heart".